1. Field of the Invention
This invention relates to fastening devices and more specifically to devices to apply tension to fastening devices such as studs, bolts and the like.
2. Description of the Prior Art
The stud tensioners of the prior art used various means and methods to attach the stud and engaging member. The attachment of the tensioner stud is an important function in the operation of the tensioning devices. Tensioners are often used on more than one fastening device when assembling or disassembling an apparatus as, for example, large pressure vessels. Therefore the tensionser must be disengaged and reengaged each time they are shifted from one fastener to another. The engaging and disengaging processes for the tensioner can be time consuming, resulting in lengthened down time for the apparatus being serviced. The increased down time results in increased expense and very often increased hazard to the personnel engaged in servicing the apparatus.
Additionally, the means for attaching prior art tensioners are often bulky and require large clearances in which to operate. Extensive disassembly of the apparatus being serviced or equipment being connected to this apparatus is necessary in order to obtain the required clearances.
Reliability of the tensioner attaching device is also an important factor. Often prior art devices required threaded connections which could easily be compromised by cross threading which resulted from even minor misalignment of the elements when engaging the tensioner.
In summary, the structure and operation of the prior art tensioners was complex and costly, and not always reliable.